Surgical Disease of the Stomach and Duodenum in Infants and Children

Incidence and Etiology

Enteric duplications may occur anywhere along the gastrointestinal tract. Gastric and duodenal duplications represent ~15% in a series spanning 31 years by Iyer and Mahour, with the remainder of enteric duplications occurring in the distal small bowel, colon, and rectum. Multiple mechanisms have been proposed, including persistent fetal enteric diverticula, incomplete recanalization following obliteration of the lumen during duodenal development, and the “split notocord” theory, whereby abnormal adhesions persist between the ectoderm and endoderm leading to herniation of the yolk sac between the vertebra, resulting in local duplication of the gut. Duplications may be saccular or tubular in morphology and may be located in the intermuscular, submucosal, or subserosal layers of the intestinal wall. They primarily occur on the mesenteric side of the involved segment and have variable communication with the lumen of adjacent bowel. Histology will demonstrate smooth muscle within the wall and a mucosal lining.

Presentation and Diagnosis

Two-thirds of patients are diagnosed within the first year of life, while many asymptomatic patients or patients with mild symptoms may remain undiagnosed until adulthood. Many of the symptoms are a result of a mass effect as the duplication grows in size from accumulating mucosal secretions. Patients may present relatively asymptomatic with a mobile mass or increasing abdominal girth. Enteric duplications may result in visceral pain or obstruction from compression of adjacent structures. Duodenal and gastric duplications can result in gastric outlet obstruction. Almost one-half of enteric duplications contain gastric mucosa, which can lead to ulceration and gastrointestinal bleeding. Pancreatitis and perforation may occur from peptic ulceration within duodenal duplications. Malignancy has been described in rare case reports.

Diagnosis of enteric duplication can be detected with enteric contrast studies. In the advent of routine antenatal imaging, increasing numbers of patients are diagnosed before birth. Both prenatal ultrasound and MRI have been used in detecting these lesions. MRI is valuable in the evaluation of associated anomalies such as cardiac, pulmonary, and spinal defects. Once the lesion is prenatally diagnosed, surveillance is important to monitor for rapid growth leading to mass effect on neighboring structures in utero ( Fig. 67.2A ).

Management

Surgical excision is the mainstay of enteric duplication management and is required in a timely fashion to relieve the symptomatic patient. Asymptomatic, prenatally diagnosed neonates can be treated electively within the first 6 months of life. Older patients with incidental diagnosis found on imaging for other reasons should undergo elective resection due to the risk of complications over a lifetime. Surgical excision can be performed through open or laparoscopic approaches. The enteric duplication may be excised alone; however, care must be taken to preserve the common blood supply with the adjacent bowel. Selective excision of duodenal duplications is particularly challenging at times because of proximity to hepatobiliary and pancreatic structures. Mucosal stripping and cyst excision or Roux-en-Y cyst-jejunostomy have been described in surgical management of these potentially difficult lesions (see Fig. 67.2B ).

Incidence and Etiology

Gastric volvulus is rare in the pediatric population with only 581 cases described in 78 years. Nonetheless, it continues to be an important pathology that must be recognized early to ensure a good outcome. The stomach is normally anchored by a number of fixation points. The gastrocolic, gastrosplenic, gastrohepatic, and gastrosplenic ligaments, along with the esophagogastric junction and pylorus, normally prevent abnormal rotation of the stomach. Failure of usual fixation can result from agenesis, laxity, or disruption of these ligaments and can lead to pathologic rotation of the stomach. Gastric volvulus may also result from gastric neoplasm, intestinal malrotation, and abnormal development of the diaphragm, spleen, transverse colon, and liver.

The stomach may rotate along two planes. Organoaxial volvulus occurs along the longitudinal axis, when the stomach rotates around the plane between the esophagogastric junction and the pylorus. The stomach will appear upside-down, with the greater curvature located superior to the lesser curve. The stomach may also rotate along the mesenteroaxial volvulus or AP plane, resulting in the antrum and pylorus anterior and superior to the esophagogastric junction. Gastric volvulus around both planes has also been diagnosed.

Presentation and Diagnosis

Gastric volvulus in pediatric population can present in either an acute or chronic fashion. Symptoms will depend on degree of twisting and acuity of volvulus. Acute gastric volvulus will most commonly present in children less than 5 years old with nonbilious emesis, epigastric pain, abdominal distention, respiratory distress, cyanosis, and hematemesis. Mortality has significantly improved with increasing awareness and prompt diagnosis with survival more than 90%. Acute gastric volvulus is commonly associated with abnormal adjacent organs. Chronic gastric volvulus is a more difficult diagnosis, with more subtle symptoms of intermittent volvulus. The most common presentation of chronic gastric volvulus is in an infant less than 1 year old with nonbilious emesis, feeding intolerance, abdominal pain, and respiratory distress.

Plain radiographs may show a dilated gastric silhouette at or above the level of the diaphragm. The orientation of the stomach may be horizontal if twisted along the organoaxial axis or vertical if volvulized along the mesenteroaxial axis. Definitive diagnosis is confirmed by a UGI study.

Management

The underlying etiology of the gastric volvulus directs medical versus surgical treatment. Acute gastric volvulus is potentially life-threatening and must be managed expediently. Fluid resuscitation and gastric decompression via nasogastric or orogastric decompression must be initiated. The goals of surgery are to reduce the volvulus, and gastropexy, and any associated intraabdominal factors predisposing to volvulus are repaired.

Chronic primary gastric volvulus may be treated nonoperatively with prone or right lateral positioning following feeding. However, in the United States, most chronic volvulus is managed surgically with gastric fixation by gastropexy or gastrostomy tube placement.

Incidence and Etiology

While paraesophageal hernia may occur as a complication following fundoplication, congenital paraesophageal hernia is a rare pathology and accounts for less than 5% of all hiatal hernias. Approximately one-third of patients will have an associated anomaly, such as intestinal malrotation, microgastria, or trisomy 21. Hiatal hernias can be classified into four types. Type I hiatal hernias are sliding hernias involving the gastric cardia. Types II, III, and IV are paraesophageal hernias. In type II, the gastroesophageal junction remains in the normal position with herniation of the gastric fundus alongside. In type III hernias, the gastroesophageal junction herniates into the thoracic cavity with the gastric fundus, and type IV hernia involves herniation of any additional intraabdominal organs, such as the colon, spleen, small intestine, or omentum.

Presentation and Diagnosis

Hiatal hernia most commonly presents with emesis and is concomitantly diagnosed with gastroesophageal reflux disease. In approximately 70% of patients with type III and IV hernias, respiratory distress will accompany gastrointestinal symptoms. Diagnosis can be suggested on chest x-ray with lateral films to differentiate between Bochdalek and Morgagni hernia. The diagnosis is confirmed on UGI study or CT scan.

Management

Congenital hiatal hernias are managed surgically with the reduction of stomach and gastroesophageal junction to the abdominal cavity and repair of the hiatus with fundoplication. The hernia sac may be redundant and adherent to thoracic structures. However, efforts to excise the hernia should be attempted, as the sac may tether intraabdominal contents and prevent successful reduction. Repair may be performed laparoscopically or through an open approach. Most often in pediatrics, the hiatal defect may be closed primarily without the use of biologic or mesh material. The esophagus may be stented with a bougie during hiatal closure and fundoplication to avoid excessive narrowing.

Incidence and Etiology

Congenital microgastria is a rare anomaly with only 63 reported cases. Microgastria is defined by a small, underdeveloped stomach with agastria representing the extreme of the spectrum with the complete absence of the stomach. Microgastria most often occurs with other anomalies, including asplenia, esophageal atresia, intestinal malrotation, cardiac defects, renal malformations, central nervous system abnormalities, laryngotracheal stenosis, bronchial clefts, and limb irregularities.

Presentation and Diagnosis

The underdeveloped stomach is unable to serve as a reservoir, leading to feeding intolerance with frequent emesis, failure to thrive, gastroesophageal reflux, and recurrent respiratory infections from aspiration. Diagnosis is confirmed with a UGI study that demonstrates a small tubular stomach in a transverse orientation and may be associated with a proximally dilated esophagus.

Management

Microgastria is initially managed medically with small-volume nasogastric feeds and medical control of associated reflux. Failure of medical management results in both short-term and long-term sequelae, including poor growth, cognitive delay, and dumping syndrome. Definitive management of microgastria has not been defined, as it is most frequently associated with other conditions. The initial goals of surgical management are to optimize nutrition and growth such as creation of a gastrojejunostomy, a feeding jejunostomy, or a Roux-en-Y feeding jejunostomy. These efforts are met with limited success with persistent poor growth and development, as well as a high occurrence of dumping syndrome. Definitive surgical treatment for congenital microgastria with improvement of dumping syndrome was initially demonstrated in 1980 with the description of the jejunal Hunt-Lawrence pouch as a Roux-en-Y limb.

Incidence and Etiology

There are several lesions that may lead to primary congenital gastric outlet obstruction including mass effect from adjacent enteric duplications or tumors. Congenital pyloric atresia is a rare cause of gastric outlet obstruction with an incidence of 1 in 100,000 births. Pyloric atresia is classified into three types. Type I is a simple luminal web or membrane. Type II is a complete atresia separated by a fibrous band. Type III involves a complete separation with a resultant gap. Forty percent of congenital pyloric atresia is accompanied by other disorders, most commonly intestinal atresia and epidermolysis bullosa ( Fig. 67.3 ).